Relay



Nov. 22, 1938, N WAGAR 2,137,818

RELAY Filed Sept. 22, 1957 INVENTOR H.N. WAGAR} A T TORNEY Patented Nov.22, 1938 UNITED STATES PATENT OFFICE RELAY Application September 22,1937, Serial No. 165,020

6 Claims.

This invention relates to relays and more particularly to relays for usein telephone systems. In electric circuits generally and in telephonecircuits particularly, electromagnetic relays are extensively employed.In such circuits the functions to be performed are numerous and variedand it is often very essential that relays employed in such circuitsshall positively make and break the circuits controlled over theircontacts.

If the contacts of a relay do not make firmly, or break cleanly, or inother words, if the contacts have a tendency to chatter when they makeor break, false operation in the circuits controlled thereover willresult.

It has been found that one of the chief factors which contributed to thetendency of relay contacts to chatter upon the release of the armatureagainst the back stop or the operation of the armature against the poleface of the relay core, is the kinetic energy stored in the armatureduring its movement. If a large part of this energy can be dissipated atthe instant of impact of the armature either against the back stop oragainst the core, then the bouncing of the armature and the transmissionof the vibration of the armature to the contact springs controlledthereby Will be reduced. It has been found from experimentation that thetendency of the relay armature to bounce or vibrate as a whole may bereduced by so forming the free end of the armature that the energystored in the armature is dissipated within the armature it self.

It is therefore the object of this invention to improve the design of anelectromagnetic relay armature so as to reduce its tendency to bounce orvibrate and to thereby reduce the chattering of contacts controlledthereby. This object is attained in accordance with the presentinvention by cleaving the forward or free end of the armature and byintroducing an energy absorbing means such as a leaf spring or a stripof cellulose stiffened silk, paper or the like between 45 the adjacentedges of the cleft portion.

The invention will be more readily understood from the following detaildescription taken in connection with the accompanying drawing in which:

50 Fig. 1 is a side elevational view of a wellknown type of relay inwhich the invention is embodied;

Fig. 2 is a top plan view of the relay of Fig. 1 with certain partsomitted; and

5 Fig. 3 is a partial plan view of a relay armature constructed inaccordance with a modified form of the invention.

The relay disclosed in Fig. 1 of the drawing is of a well-known typeconsisting of a core I secured at its rear end to a heel-piece ormounting 5 bracket 2, an energizing coil 3 surrounding the core I, anarmature 4 having front and rear cross members and side arms unitingsaid members, the forward cross member of which cooperates with the poleface 5 of the core I and 10 the rear cross member of which is riveted toa reed hinge 6, coil terminal lugs I and a spring pile-up on each sideof the relay coil, each comprising two or more contact springs such as 8and 9. The reed hinge 6, coil terminal lugs I and springs 8 and 9 aresuitably clamped to the mounting bracket 2 by screws I0 and I I whichpass therethrough and through the clamping plates I2 and I3. Forinsulating the terminal lugs and contact springs from each other, from20 the bracket 2 and from the clamping plates I2 and I3, strips I4 ofinsulating material are interposed. For engaging the contacts of springs8 and 9 of each spring pile-up upon the attraction ofv the armature 4toward the core I, the arma- 25 ture is provided near its forward endwith operating studs I5 of insulating material.

To limit the movement of the armature 4 away from the core I upon thedeenergization of the coil 3 and to afiord means for adjusting the 30normal air-gap between the front cross member of the armature 4 and thepole face 5 of the core I, the back stop screw I6 carrying the back stopnut I! is provided. The back stop screw is L-shaped having itshorizontal arm seated in the end of the core I and its vertical armthreaded to receive the back stop nut IT.

The forward cross member of the armature 4 is cleft, as indicated at I8,so that each side arm of the armature may be attracted to the pole face5 of the core I substantially independently of the other side arm exceptas restrained by the integral rear cross member joining the rear ends ofthe side arms. Interposed in the cleft 98 between the adjacent edges ofthe side arms 5 is a friction member I9 which may be a leaf spring or astrip of cellulose acetate stiffened silk, paper or other material heldin place by any suitable manner as by a rivet.

With the relay armature so constructed, when it strikes the back stopnut I'I, one side arm tends to vibrate with respect to the other and thevibratory movement between the two arms is damped by the frictionalengagement with the insert I9 positioned in the cleft I8 between theside arms.

The kinetic energy stored in the armature during its movement toward theback stop is thus dissipated at the moment of impact between thearmature and the back stop nut and the tendency of the armature torebound from the back stop nut and to transmit its rebound movementthrough the operating studs I5 to the contact springs is reduced.Similarly, the energy stored in the armature during its attractivemovement toward the core is dissipated at the moment of impact betweenthe arms of the armature with the core.

As an alternative construction the cleft I8 dividing the forward crossmember of the armature may be made diagonally in such a manner as tounbalance the masses of the two side arms of the armature. In thismodified construction a similar friction insert i9 is interposed withinthe cleft between the adjacent walls of the cleft.

What is claimed is:

1. In an electromagnetic structure, a heel-piece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having two side arms, said arms being hinged atone end to said heelpiece and having their free ends extending injuxtaposition over the pole face of said core, and friction meansinserted between adjacent edges of the juxtaposed ends of said arms.

2. In an electromagnetic structure, a heelpiece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having two side arms, said arms being hinged atone end to said heelpiece and having their free ends extending injuxtaposition over the pole face of said core, and a strip of springmaterial inserted between the adjacent edges of the juxtaposed ends ofsaid arms.

3. In an electromagnetic structure, a heel-piece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having two side arms, said arms being hinged atone end to said heelpiece and having their free ends extending injuxtaposition over the pole face of said core, and a leaf springinserted between the adjacent edges of the juxtaposed ends of said arms.

4. In an electromagnetic structure, a heelpiece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having two side arms, said arms being hinged atone end to said heel-piece and having their free ends extending injuxtaposition over the pole face of said core, and a cellulose acetatestiffened friction member inserted between the adjacent edges of thejuxtaposed ends of said arms.

5. In an electromagnetic structure, a heelpiece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having a rear cross member, a front crossmember overlying said pole face and two side arms uniting said crossmembers, said rear cross member being hinged to said heel-piece and saidfront cross member being cleft, and friction means inserted within saidcleft and in frictional engagement with the adjacent edges thereof.

6. In an electromagnetic structure, a heelpiece, a core secured to saidheel-piece extending forwardly therefrom and having a pole face on itsforward end, an armature having a rear cross member, a front crossmember overlying said pole face and two side arms uniting said crossmembers, said rear cross member being hinged to said heel-piece and saidfront cross member being diagonally cleft, and friction means insertedwithin said cleft in frictional engagement with the adjacent edgesthereof.

HAROLD N. WAGAR.

